1. Field of the Invention
The present invention generally relates to devices for optically connecting the ends of waveguides such as optical fibers, and more particularly to a tool which is used to actuate an optical fiber splice.
2. Description of the Prior Art
Splice devices for optical fibers are known in the art, but there is still a need for a quick and reliable method of splicing not only discrete fibers, but also a plurality of fibers in a high density environment. The present invention relates not to the splices or connectors per se, but rather to a tool which is used to operatively place fibers in a splice or connector.
Many alternative splice designs exist, and several of these designs require, or are advantageously used with, special assemblies or tools for preparation of the fibers and creation of the splice. For example, an early patent to Cherin et al. U.S. Pat. No. 4,028,162) describes the use of inclined ramps to guide a plurality of fibers in two ribbon cables towards a plastic substrate having fiber-receiving grooves. An embossing head is then used to clamp a cover plate over the grooved substrate. Another tool used in joining multiple fiber ribbons is depicted in U.S. Pat. No. 4,123,137 issued to E. Marcatili, and includes two holders having alignment pegs for the ribbons, one of the holders being slidable along a pair of rods to cause a first ribbon to abut a second ribbon. A grooved cover plate helps align the fibers during curing of a bonding material.
Two assembly tools or jigs for discrete fiber splices are disclosed in U.S. Pat. Nos. 4,940,307 (Aberson et al.) and 5,029,972 (Lukas et al.). The jig of Aberson is fairly simple, essentially only a holder having two arms with slots which receive ribs on the underside of the splice body. The Lukas jig, however, is more complicated. That jig has a slot used to secure a special splice body, and two adjacent fingers which are used to push a gripping member in the body that overlies the splice area. A lever having a roller at the operative end is used to actuate both the fingers and a compression member disposed opposite the fingers with respect to the splice body. When the lever is moved to a first position, the roller indirectly causes the fingers to push the gripping member away from the splice area, easing insertion of the fibers. When the lever is moved to a second position, it forces the compression member against the opposite side of the gripping member, pushing the gripping member toward the fibers and clamping them. The jig also has a pair of slitted foam blocks for supporting the fibers proximate the splice area.
Another device, which is reminiscent of the Lukas jig and, with Lukas, probably represents the closest prior art, is the assembly tool sold by Minnesota Mining and Manufacturing Company (3M, assignee of the present invention) which is in conjunction with the FIBRLOK optical fiber splice (FIBRLOK is a trademark of 3M. That tool has a cradle area for receiving the FIBRLOK splice body, and foam retention pads adjacent the splice area for supporting the fibers. A lever pivots over and onto the upper surface of the cradled splice body; the lever has a compression surface which forcibly contacts the cap of the FIBRLOK, and snaps it into an actuated position.
While the foregoing tools are particularly useful with their corresponding splice designs, none of these tools are designed for use with a mechanical splice requiring longitudinal movement of an actuation element. Specifically, none of these tools may be used in conjunction with the MF.sup.2 multiple fiber splice (MF.sup.2 is also a trademark of 3M) which is disclosed in U.S. Pat. No. 5,151,964 (this application is not prior art). It would, therefore, be desirable and advantageous to devise a splice assembly tool which may provide longitudinal actuation of a mechanical splice. The tool should preferably facilitate visual confirmation that the fibers have been properly aligned with the splice prior to insertion of the fibers into the splice, and further provide positive abutment of fibers which are inserted into the splice to minimize signal loss across the splice.